The present invention relates generally to image projectors. In particular, the present invention relates to military type image scene projectors. In greater particularity, the present invention relates infrared image scene projectors.
A good deal of military and communications weaponry today relies upon infrared imaging and acquisition techniques. For example, missile targeting systems rely upon templated infrared signatures to lock onto aircraft exhaust signatures, helicopter gun ships use tank heat signatures to lock onto targeted vehicles, and military aircraft navigation aids use infrared sensors to assist in auto-navigating through rough terrain and inclement weather. In more complex systems, such as satellite imaging, navigation element tracking, and forward looking infrared (FLIR) navigation systems, recorded infrared scenes are compared to live sensory data for real-time decision making. In general, infrared image sensing signatures of geography, buildings, and even people will likely become a major component in target acquisition and locking systems; and it is expected that various sorts of weaponryxe2x80x94missiles, artillery, navigation, and rifle targeting systemsxe2x80x94will utilize infrared imaging in some form or fashion in the future.
Infrared image sensors detect electromagnetic radiation from a scene and output electrical or optical information extracted from the scene. Lenses associated with a selected imaging system focus infrared radiation upon one or more sensors so that acceptable signal capture is obtained. However, while image detection has been advanced due to improvements in infrared focal plane arrays (FPAs) and advanced optics design, a great deal of attention is now being drawn to the design of software for image recognition and decision making based upon received images. Sophisticated software analyzes received images and makes logical determinations based upon pre-established criteria, such as object templates, spectrum signatures (e.g. frequency signatures), and intensity to analysis.
Testing of infrared imaging systems can be as complex as the imaging design itself. Most production testing methods inject an electrical test signal for a sensor system to process and compare system component responses based upon an expected result. However, signal injection is not an optimum test method because the image detector with its related electronics and associated gimbals and optics are not tested. The optics and detector of the system are usually tested separately using a very simple static scene or test pattern, or with a very slow moving, but somewhat more complex series of synthetic scenes. This two-part test methodology does not perform an end-to-end test of the entire system and is inferior to providing live scene image testing data. Hence, as the quantity and complexity of such systems has increased the need for generating and projecting synthetic images for input into image sensors has also grown.
Several systems are now available capable of presenting realistic, detailed infrared images or xe2x80x9cscenesxe2x80x9d into the field of view of the sensors being tested for a selected system. For example, Kenyon U.S. Pat. No. 6,123,288, has developed a system to provide flicker-less projection of infrared scenes using a non-volatile electron beam addressed light-valve output. Leddy, U.S. Pat. No. 5,457,493, has developed a micro-mirror based image simulation system in which a digital micro-mirror reflects infrared energy from a separate infrared source onto a testing subject. And, Billingsley, U.S. Pat. No. 4,530,010, has designed a dynamic infrared scene projector using thin films of vanadium dioxide which are excited to produce infrared images.
However, each of these designs and others currently available in the industry suffer from several drawbacks, namely: (1) none of the currently available systems allow for easy mobile transport of a scene generator; (2) none allow for solid state generation of scene images on location and at reduced atmospheric pressures; and (3) none provide a self-contained, compact design that is capable of self-generation of images without external stimulus. Hence, military systems utilizing infrared sensory electronics cannot be easily tested in the field and do not include the ability for continuous live testing in airborne vehicles.
Moreover, one of the most desired testing methods for testing defense armaments and navigation systems is xe2x80x9cbuilt-in-self test (BIT). However, BIT is most useful if the testing hardware can be utilized in the field in the typical environment of the system. For example, if a scene projector could be integrated into a FLIR system, live pre-flight or in flight testing could be accomplished to ensure the integrity of the system""s operation. BIT could also allow relatively easy refinements to existing imaging systems and allow the enhancement of on-board software recognition systems, thereby increasing the effectiveness of the current infrared sensory electronics.
Therefore, what is needed is a compact, self-contained infrared scene projector that can be configured to test infrared imaging systems in the field and during live operations.
It is the object of the present invention to provide a solid state, self-contained infrared scene projector.
It is another object of the present invention to provide an infrared scene projector that can internally create infrared scene images for projection onto a target testing object.
It is still another object of the current invention to provide an infrared scene projector that can receive image commands from an external computer for projection.
It is yet another object of the current invention to provide an infrared scene projector that can receive external video source imagery and project such source imagery.
It is still another object of the current invention to provide an infrared scene projector that can provide internal cooling for an infrared pixel array and thereby properly regulate infrared background temperatures of projected solid objects.
It is still another object of the current invention to provide an infrared scene projector that allows for interchangeable optics.
It is still another object of the current invention to provide an infrared scene projector that can be integrated with a mirrored collimator for multi-spectral projection of scene imagery.
In summary, the present invention is a relatively small and compact infrared scene projector. An external power supply powers the projector unit and an integrated RS-232 serial port on the projector allows for reception of commands from a connected personal computer. The projector utilizes a digital signal processor to control the internal electronics and for generation of preprogrammed infrared objects. A processor assembly card and a scene projector assembly card communicate internally to control a thermoelectric cooling (TEC) device and an electronic infrared projector array to project flicker free, high resolution infrared images onto a targeted sensor for testing. Optics in the form of interchangeable lens or a mirrored collimator allow for projection of an array generated image onto a live test object. Internal high speed memory and electrically erasable firmware, both externally programmable, allow for on-the-fly programming and self-contained operation. The projector can be co-located with military electronics that utilize infrared sensory imagery to provide field located built in self test (BIT).